The cell is one of the oldest nanomachines capable of independent life. Multicellular organisms are communities of cells where each member is capable of responding to its environment but also communicating change to surrounding members of the same community. Cellular systems are complex and carry out a multitude of functions in response to the environment and that directly affect the cellular environment. For example, cells are capable of many complex functions such as motility, cell-cell communication, synthesis of chemicals and macromolecules, and reproduction.
The cell membrane or the cell wall is a fluid and dynamic structure through which all drugs, biochemicals, ions, and cellular signals must pass. Cell membranes are flexible and can assume many different morphologies, depending on cell type and function.
Cellular nanomechanics have been a recent area of study ushered in with the advent of the Atomic Force Microscope (AFM). Force-Volume Imaging, Nano-indentation and Force Spectroscopy have all yielded information regarding the mechanical stability and integrity of cellular membranes in response to normal physiological conditions as well as to stress. However, the currently available methods provide information only about movement of a whole cell, or about the mechanical properties of a cell.
There is a need in the art for methods of determining a characteristic of a cell (e.g., determining the physiological status or biological state of a cell; determining the cell type of a cell; determining the response of a cell to a biochemical event; etc.). The instant invention addresses this need by providing methods of detecting movement of a membrane in a cell, as a readout for the biological state of a cell.
Literature
Domke et al. (1999) Eur. Biophys. J. 28:179-186; Domke et al. (2000) Colloids and Surfaces B:Biointerfaces 19:367-379; Zhang et al. (2001) Nature 413:428-432; A-Hassan et al. (1998) Biophys. J. 74:1564-1578; Rotsch et al. (1997) Cell Biol. Int. 21:685-696; Binnig et al. (1986) Phys. Rev. Lett 56:939-933; Charras et al. (2002) Biophys. J. 82:2970-2981.